Re: Centos 7.0 and mismatched swap file

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]



On 2015-02-15, Gregory P. Ennis <PoMec@xxxxxxxxx> wrote:
>
> I am putting together a new mail server for our firm using a SuperMicro
> with Centos 7.0.  When performed the install of the os, I put 16 gigs of
> memory in the wrong slots on the mother board which caused the
> SuperMicro to recognize 8 gigs instead of 16 gigs.  When I installed
> Centos 7.0, this error made the swap file 8070 megs instead of what I
> would have expected to be a over 16000 megs.

You lucked out, honestly.  You really don't want 8GB of swap on your
system.  What will most likely happen is that you'll have a process that
starts running away eating memory, and it'll try to use all of that swap
before the kernel's OOM killer can kick in.  You will not enjoy
thrashing 8GB of swap for probably hours.

Really what you should do is drastically reduce the amount of swap you
have allocated, and reclaim most of that 8GB of swap space for storage
filesystems.  In my experience, a few hundred MB of swap is more than
sufficient to be able to swap out seldom-used memory while not taking
too long to OOM.  If you really find a need for more swap later, you can
allocate a swap file; it's slightly less efficient than a swap
partition, but compared to real memory the difference will be
negligible.

--keith

-- 
kkeller@xxxxxxxxxxxxxxxxxxxxxxxxxx


_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos




[Index of Archives]     [CentOS]     [CentOS Announce]     [CentOS Development]     [CentOS ARM Devel]     [CentOS Docs]     [CentOS Virtualization]     [Carrier Grade Linux]     [Linux Media]     [Asterisk]     [DCCP]     [Netdev]     [Xorg]     [Linux USB]
  Powered by Linux